diff --git a/src/main/java/com/linkurlshorter/urlshortener/security/CustomUserDetailsService.java b/src/main/java/com/linkurlshorter/urlshortener/security/CustomUserDetailsService.java
index 42d2f58..563e7be 100644
--- a/src/main/java/com/linkurlshorter/urlshortener/security/CustomUserDetailsService.java
+++ b/src/main/java/com/linkurlshorter/urlshortener/security/CustomUserDetailsService.java
@@ -1,10 +1,11 @@
 package com.linkurlshorter.urlshortener.security;
 
-import com.linkurlshorter.urlshortener.user.model.User;
-import com.linkurlshorter.urlshortener.user.UserService;
+
+import com.linkurlshorter.urlshortener.user.UserRepository;
 import lombok.RequiredArgsConstructor;
 import org.springframework.security.core.userdetails.UserDetails;
 import org.springframework.security.core.userdetails.UserDetailsService;
+import org.springframework.security.core.userdetails.UsernameNotFoundException;
 import org.springframework.stereotype.Service;
 
 /**
@@ -16,7 +17,7 @@
  *
  * @author Egor Sivenko
  * @see org.springframework.security.core.userdetails.UserDetailsService
- * @see UserService
+ * @see UserRepository
  * @see SecurityUserDetails
  */
 @Service
@@ -24,9 +25,9 @@
 public class CustomUserDetailsService implements UserDetailsService {
 
     /**
-     * Service for managing user-related operations.
+     * Repository for managing user-related operations.
      */
-    private final UserService userService;
+    private final UserRepository userRepository;
 
     /**
      * Loads user details by their email address.
@@ -36,7 +37,9 @@ public class CustomUserDetailsService implements UserDetailsService {
      */
     @Override
     public UserDetails loadUserByUsername(String email) {
-        User user = userService.findByEmail(email);
-        return new SecurityUserDetails(user);
+        return userRepository
+                .findByEmail(email)
+                .map(SecurityUserDetails::new)
+                .orElseThrow(() -> new UsernameNotFoundException(email));
     }
 }
diff --git a/src/test/java/com/linkurlshorter/urlshortener/TestConfig.java b/src/test/java/com/linkurlshorter/urlshortener/TestConfig.java
index fb6841b..420c93c 100644
--- a/src/test/java/com/linkurlshorter/urlshortener/TestConfig.java
+++ b/src/test/java/com/linkurlshorter/urlshortener/TestConfig.java
@@ -37,14 +37,14 @@ public JwtUtil jwtUtil() {
     }
 
     /**
-     * Creates a bean for CustomUserDetailsService with a mocked UserService dependency.
+     * Creates a bean for CustomUserDetailsService with a mocked UserRepository dependency.
      *
-     * @param userService UserService mock bean
-     * @return CustomUserDetailsService bean with mocked UserService dependency
+     * @param userRepository UserRepository mock bean
+     * @return CustomUserDetailsService bean with mocked UserRepository dependency
      */
     @Bean
-    public CustomUserDetailsService customUserDetailsService(UserService userService) {
-        return new CustomUserDetailsService(userService);
+    public CustomUserDetailsService customUserDetailsService(UserRepository userRepository) {
+        return new CustomUserDetailsService(userRepository);
     }
 
     /**
diff --git a/src/test/java/com/linkurlshorter/urlshortener/auth/AuthControllerIntegrationTest.java b/src/test/java/com/linkurlshorter/urlshortener/auth/AuthControllerIntegrationTest.java
index af236b1..9c72c67 100644
--- a/src/test/java/com/linkurlshorter/urlshortener/auth/AuthControllerIntegrationTest.java
+++ b/src/test/java/com/linkurlshorter/urlshortener/auth/AuthControllerIntegrationTest.java
@@ -76,7 +76,7 @@ void loginFailedWhenUserDoesNotExistTest() throws Exception {
                         .content(objectMapper.writeValueAsString(authRequest)))
                 .andExpect(MockMvcResultMatchers.status().is4xxClientError())
                 .andExpect(MockMvcResultMatchers.jsonPath("$.statusCode").value(401))
-                .andExpect(MockMvcResultMatchers.jsonPath("$.message").value("No user by provided email found"));
+                .andExpect(MockMvcResultMatchers.jsonPath("$.message").value("Bad credentials"));
     }
 
     /**